[dayneger]

In the GR Research circle I started a thread about trying to make a different version of their NX-Oticas (MTM) and GR/Rhythmik servo subs.  However, some of the questions might fit better in the broader OB circle here. 

Trying to keep things compact, short, and visually integrated, I'm exploring a ripole-similar servo sub configuration and possibly adding regular woofers leveraging similar principles as well.  More details on my design goals here:  https://www.audiocircle.com/index.php?topic=184961.0

The shorter version without the midbass drivers could look like this:



with a cross-section like this:



Since the "regular" NX-Otica has those 4x midbass drivers, I was thinking about adding 2x per side to help out that frequency range (approximately 80-300 Hz):

[dayneger]

1.  Are there any reasons to believe/not believe that this kind of sub configuration would work using the GR servo drivers and matching Rhythmik amps?  For reference, as shown the cross-section of the output zone is a fairly consistent 1/3 of the combined Sd piston area of the 2 drivers and the front-back depth of the outer sidewalls is 16" (40 cm).

2.  Could the midbass drivers function properly and integrate as shown?  Is there an upper bound for the frequency range of these driver layouts, and if so, where might it be?  What issues would you expect?

[Jazzman53]

I'm late to the party on this response but it warms my heart to see Ripol designs gaining popularity.  And it's especially interesting to see the Ripol concept integrated into a full-range speaker like this one. 

I'm thinking the woofers' response would be the ultimate limit of the Ripol's frequency response but its chamber resonance would be a much lower, practical limit if one wishes to avoid it by choosing an octave lower crossover point, rather than a notch filter. 

I use a pair of Ripol subs which blend seamlessly with my DIY hybrid ESLs, which also have OB mounted woofers.
I cross them in at 70Hz to avoid the chamber resonance (a nasty-loud peak at 299Hz). 

Not everyone appreciates Ripol's because they don't hit you in the chest like a sledge hammer but I LOVE them. 
They are simply the cleanest sounding, most non-boomy subs I've ever heard. 

I'm looking forward to seeing some photos of your finished speakers! 

[RonP]

What will be the effects of rotating the Ripole drivers 90 degrees to horizontal? Normally I've seen the Ripole drivers vertical. Is the sound radiating pattern here good/doable with them on their side?